Telegraphy.



E. KEEN.

TELEGRAPHY.

APPLICATION FILED vMAR. 8, 1910.

Patented Mar. 21, 1916.

9 SHEETS-SHEET l.

INVENTOR SSE-*Mmm* is AUORNEY E. KEEN.

TELEGRAPHY.

APPLICATION FILED MAR. s, 1910.

Patented Mar. 21, 1916.

9 SHEETS-SHEET 2.

lNVENTUR WITNESSES:

GM /fs ATTORNEY E. KEEN.

TELEGRAPHY.

APPLICATION FILED MAR. 8, 1910.

Patented Mar. 21, 1916.

9 SHEETS-SHEET 3.

www.

E K @n En w mm NQ @Q www w PQ WQ m w m w /s ATTORNEY E. KEEN.

TELEGRAPHY.

APPLICATION FILED MAR. 8. |910.

Patented Mar. 21, 1916.

9 SHEETS-SHEET 4- f WITNESSES E. KEEN.

TELEGRAPHY.

APPLICATION FILED M1111. 8. 1910.

1,176,148. Patented Mar. 21,1916.

9 SHEETS-SHEET 5.

FIG 15.

/20 WTNESSES.' 12] /ZZ 776 /NVE/V T 0l? MJL/@ew E. KEEN.

TELEGRAPHY.

APPLICATION man MAR.8.1910.

l 1 76, 1 48. Patented Mar. 21, 1916.

9 SHEETS-SHEET 6.

FIG 16.

7M/ffm y www. L 737 Q @im E. KEEN.

TELEGRAPHY.

APPLICATION FILED MAR. E. |910.

Patented Mar. 21, 1916.

9 SHEETSSHEET 7.

FIG 19.

FIG Z1 FIGZO.

67 /520 @e Ill-g FIGZZ.

W/TNESSES:

wh /ffJ A HNEY E. KEEN.

TELEGRAPHY.

APPL|cAT|oN FILED MAR. 8. 1910.

Patented Mar. 21, 1916.

9 SHEETS-SHEET B.

.mm ,ITH

n v QM //S ATTORNEY 6am/25H03 l Br if f WIT/VESSES:

E. KEEN.

TELEGRAPHY.

APPLICATION mso MAR. 8, |910.

Patented Mar. 21, 1916.

9 SHEETS-SHEET 9.

INVENTO? UNITED', sTATEs PATENT oEEIoE.

ELIOT KEEN, OF NEW YORK, N. Y., ASSIGNOR T0 TELEGRAVURE COMPANY, A

CORPORATION 0F NEW YORK.

TELEGRAPHY.

Specification of Letters Patent.

Patented Mar. 21, 1916.

T 0 all whom it may concern.' I

Be it known that I, ELIOT KEEN, a citizen of the United States, residing in the borough of Manhattan` in the city, county, and State of New York, have invented certaln new and useful Improvements in Telegraphy, of which the following is a specilicatlon.

My invention relates to improvements in the art of telegraphy and more particularly to a certain novel method and to apparatus for performing the same especially adapted to the transmission and reproduction of plctures. Certain features of my invention are, however, of more general application.

In the attempts which have heretofore been made in the direction of transmitting pictures, many difficulties have been met with which have appeared insurmountable, among the chief of which may be mentioned the difficulty of securing that degree of synchronism between the sending and receiving machines required by all processes of which Il am aware, previous to mine; the necessity for the most accurate construction and delicate adjustment in all forms of apparatus as previously constructed; the impracticability of operating the mechanism at any efficient speed, or of transmitting pictures through repeaters or the other standard apparatus found in existing telegraphic circuits; or in any apparatus in which a make and break circuit is used, successive impulses being designed to reproduce successive parts of the picture, the inability to transform the impulses into a record corresponding with a ysatisfactory degreesof accuracy to the original picture. I overcome all of the foregoing difficulties, and also many others which lhave been heretofore found to ,preclude the practical operation of devices of this character in a manner which will be clear on perusal of the following specification.

In the accompanying drawings, `which form a part of this specification, I have chosen to show for purposes of illustration certain forms of my improved mechanism,

which illustratewhat I now consider the preferred embodiment thereof, but I do not wish to be limited thereto, as my improvements in process may be carriedv out by many other forms of apparatus, and my apparatus is capable of wide modification.

In these drawings Figure 1 is a plan view of my preferred form of transmitting apparatus; Fig. 2 is a transverse section of the same taken on line II-II of Fig. 1; Figs. 3 and 4 are, respectively, detail sectional views taken on lines III-III and IV-IV of Fig. 1; Fig. 5 is an end elevation and Fig. 6 a side elevation of my receiving apparatus; Fig. 7 is a detail view of the sprocket and ratchet wheels used for driving the receiving machine at half speed; Fig. 8 is a plan view of a portion of the receiving apparatus showing the movable armature and the means for operating the same; Fig. 9 is a detail sectional view of a portion of the armature moving mechanism; Fig. 10 is a detail plan View of the armature stop and fixed contact; Fig. 11 is a perspective view of the record-lilm-box; Fig. 12 is a detail view of a portion of the same, parts being broken away; Fig. 13 is an elevation of parts of my receiving machine looking at the same fromthe opposite side to that illustrated in Fig. 6'` and showing thel means for rotating the film carrying drum and for moving the same and its containing box longitudinally; Fig. 14 is a view partly in transverse section of the diaphragm box and i film box; Fig. 15 is a sectional plan view of the diaphragm box; Fig. 16 isa detailed view of one form of aperture forming diaphra gms which I may use in my receiving machine; Fig. 17 is a diagrammatic view illustrating the location of these diaphragms and the path of a light beam controlled by them and directed upon the record film; Fig. 18 is a rear elevation illustrating in detail a different form of aperture forming device` this being the form shown in Figs. 14 and 15; Fig. 19 is a detailed elevation of a delaved circuit closer; Figs. 20, 21 and 22 are detail views illustrating the positively driven switch controlling the end of the line synchronizing mechanism; Fig. 23 is a diagram v roo locating diaphragms used in connection with the diaphragm shown in Fig. 24.

Referring to the drawings in detail, and particularly to the transmitting mechanism illustrated in Figs. 1 to 4, the numeral l designates a base plate, upon which are mounted frames 2 and 3, carrying suitable bear- `ings in which are journaled shafts 4, 5, 6, and 7. Shafts 5 and 6 are preferably provided with longitudinal key-ways. 8 and have slidably mounted thereon pulleys 9 and 10, provided with feathers 11, sliding in the key-ways. These pulleys are'mounted in a guide frame comprising the side bars 12 and 13, connected at their ends to the split nuts 14 and 15, which engage with the screw shafts 4 and 7. The split nuts are formed of two halves pivoted on pins 16, screws 17 beingprovided to open and close these split nuts, thus causing them to engage or disengage the screw shafts. Carried by the pulleys 9 and 10 is the band 18, preferably of thin metal, and provided with a ,plurality of contact points or brushes 19, which pass over the surface of the plate 20. The plateJ 20, or sending plate, is prepared in such manner that it presents a number of conducting and non-conducting portions, or raised and depressed portions, corresponding to the picture or message to be sent. This plate 20 usually takes the form of a half-tone prepared by the well-known process of photographing a picture through a half-tone screen, and either etched or simply having the half-tone impression photographed thereon in some suitable form of enamel or non-conducting chemical preparation. As indicated, the half-tone comprises a number of dots 21, of different sizes, on a blank background. The picture may be either a positive or negative, that is, the dots p, may be conducting spaces and the background non-conducting space, or vice versa.

In the further description of this apparatus I will treat the dots as being conducting spaces. Means are provided for insulating the plate 20 from the rest of the apparatus, these means preferably taking the form of a carriage of insulating ymaterial to which the plate is secured. The carriage is movably mounted upon the base 1 and is held between 'springs 22 and thumb screws 23 in order to permit it 'and the plate 20 to be adjusted to bring the centers of the rows of dots on the latter beneath the -points or brushes 19. A pair of flat springs 24 or equivalent means may be provided to press against the band 18 to regulate the tension of the latter and prevent the same from becoming slack.

For rotating the shafts 5 and 6, and with them the pulleys 9 and 10, thus causing the band 18'to move, and the points 19 to traverse the plate 20, I. provide the Shafts 5 and 6 with `a worm gear 25, these Wormgears being engaged, respectively, by two worms 26 and 27 carried on the ends of a shaft 28. Shaft 28 is driven through suitable'gearing 29 from the clutch shaft 30, which carries the clutch members 31 and 32, the former being slidably mounted upon the shaft, but held from rotation thereupon by means of a key 33, sliding in a key-way 34. The clutch member 32 is free to rotate upon the shaft and has connected to it the gear 35 receiving power from the driving pinion 36 mounted upon the shaft 37, which may be the armature shaft of an electric motor, or any other suitably driven shaft. The clutch member 31 is normally held in engagement i with the clutch member 32 by means of a spring 38 mountedJ upon the shaft 30 and abutting against a collar 39 fixed thereto.

40 is an electro-magnet, which when energized serves to draw the clutch member 31 out of engagement with the clutch member 32, thus permitting the latter to revolve freely on the shaft 30, which remains lstationary. The screw shafts 4 and 7 are pref` erably rotated from shafts 5 and 6, through gears 41 secured to the latter, which engage gears 42 carried by sleeves 43 rotatably mounted upon the end portions of shafts 4 and 7, these sleeves having fixed thereto collars 44 to which are pivoted pawls 45. The latter engage ratchet wheels 46, fixed to the /screw shafts 4 and 7. Through this mechanism the rotation of the shafts 5 and 6 will cause the rotation of the screw shafts 4 and 7, but because of the ratchet connections above described, the latter shafts may be rotated by hand independently of the shafts 5 and 6, to permit an adjustment of the guide frame 12-13 and the pulleys 9 and 10. The points or brushes 19 may thus be brought into proper position for starting the sending operation.

In order to transmit an electrical ,make

and break impulse by means of this apparatus, the wire 47 of an electric circuit is connected to some part of the apparatus which is in electrical connection with the points 0r brushes 19, as, for instance, to the binding post 48 secured to the frame member 3. The other circuit wire49 isconnected to the plate 20, as by means of the binding ost 50. As the plate 20 is insulated from the 'rame members and 3, and the parts carried thereby, the circuit is closed only when one of the brushes 19 is in engagement with one of the conducting dots 21. The wire 47 leads to a relay 51 which is connected by wire 52 with a relay 53, a wire 54 leading from the latter to one side of the battery 55, to the other side of which is connected the wire 49. 56 and 57 are the main line wires, wire 56 being connected to the armature 58 of the relay 51. A wire 59 connects the contact of this relay with the magnet of relay 60, to which the other main line wire 57 leads. A wire 61 connects the armature 62 of the relay 60 with the clutch magnet 40, the circuit through the latter being completed through wire 63, battery 64, wire 65, armature 66 of relay 53, and wire 67 connecting the contact of relay 53 with the back contact 68 of relay 60. It will thus be seen that when one of the brushes 19 reaches one of the conducting dots 21, the circuit will be closed through the brush 19, band 18, pulleys 9 and 10, shafts 5 and 6, frame 3, wire 47, relay 51, wire 52, relay 53, wire 54, battery 55 and wire 49 back to the plate 20. Relays 51 and 53 will thus be energized, the former acting to draw over the armature 58, thus closing the main line circuit through wire 56, armature 58, wire 59, relay 60, wire 57, and suitable apparatus at the other end of the line to be hereinafter described. The closing of the two circuits as above described, While energizing relay 53 with the result of connecting wires 65 and 67 through the armature 66 of relay 53, also energizes relay 60, thus breaking the circuit between wire 67 and wire 61 by the action'of relay 60 in drawing its armature 62 away from the back contact 68. The circuit through the clutch magnet 40 thus remains broken, the clutch remains operative, and power is transmitted to the sending mechanism. If, however, one of the brushes 19 is in contact with one of the dots 21, and the main line circuit 56, 58, 59, 60, 57 is broken at the receiving station, or at any point in the line, relay 60 will cease to be operative, and the armature 62 will be drawn back by its spring against the back contact 68. The circuit will thus be closed through 62, 68, 67, 66, 65, 63, clutch magnet 40 and wire 61. Clutch member 31 will now be drawn back out of contact with clutch member 32, and the latter, with gear 35, will revolve freely, thus permitting the sending apparatus to stop.

Referring now to the receiving mechanism, the latter preferably comprises in general terms a. sensitized film and means for exposing successive portions of the same to a beam of light having a size, intensity or duration proportionedto the impulse sent over the main line Wires by the sending apparatus. As will be apparent, however, other than photographic recording means may be used for carrying out my invention under some circumstances. A preferred form of my receiving apparatus is constructed as follows: 69 is an electric motor, or other suitable source of power, which drives through a chain 70, a sprocket 7l fixed to a clutch member 72, the sprocket and clutch member being rotatably mounted upon a shaft 73. The latter is journaled in suitable bearings in the main frame 74 of the receiving apparatus and has splined upon it a clutch member 75 adapted to be normally held in engagement with the clutch member 72 by a spring 76. An electromagnet 77 serves, when the circuit is completed through it in a manner to be hereinafter describedto draw the. clutch member 75 out of engagement with the member 72, thus permitting the latter and the sprocket 71 to revolve freely. The shaft of the motor 69 also carries a sprocket 78 which drives through a chain 79 a sprocket 80 mounted on the shaft 73. The sprocket 80 is arranged to drive the shaft when rotated in one direction, for this purpose having pivoted to it a pawl 81 held in engagement by means of a spring 82, with a ratchet wheel 83 fixed to the shaft. When the shaft is rotating faster than the sprocket, however, the, pawl on the latter will simply snap over the teeth on the ratchet wheel. The latter condition arises whenever the circuit through clutch magnet 77 is broken, thus permitting shaft 73 to `be driven through chain and clutch gear 71, as the sprockets are so proportioned that the speed of shaft 73 when driven through chain 70 will be twice what it is when driven through chain 79. It will thus be seen that the effect of closin the circuit through clutch magnets 77 W1ll be to substitute for one driving means another acting to drive the apparatus at half speed.

Upon the shaft 73 is mounted a worm 89, which meshes with a worm gear 90, splined to the shaft 91. The latter is slidably and rotatably supported in suitable bearings, and preferably has one end squared as i11- dicated at 92. 93 is a drum adapted to carry upon its surface a sensitized film 94, some means, such as a key 95 entering a slot in the drum, being provided to secure the film to the drum. Inorder to avoid the necessity for' mounting the entire receiving apparatus in a dark room, the drum 93 is supported in a light proof box 96. the drum being provided with hubs 97, which proiect through the end walls of -the box and are rotatably mounted therein. The hubs 97 are preferablv provided with square sockets 98, one of which is adapted to receive the square head 92 of the shaft 91, a set screw 99 being provided to hold the end of the shaft in the socket. Rotation is thus transmitted from the'gear 90 to the drum 93. The socket 98 at the other end of the drum receives the squared end 100 of a screw shaft 101, the latter passing through a threaded opening in the fixed nut or bracket 102. JThe box is preferably provided on its under surface with bearing blocks 103 adapted to slide upon longitudinal guide bars 104. As will be apparent. the shaft 101 is rotated with the drum 93, and through its engagement with the bracket 102 moves the drum 93 and the box 96 in which it is mounted. longitudinally. The box is provided with a horizontal slit 105, which registers with an -wall 107, any suitable means being pron vided for insuring the exclusion of light from the cracks between the lbox and the wall. This may\ advantageously be done by covering either the side of the wall as indicated at 108, or the side of the box, or both, with a layer of velvet or like material. For closing the slit 105 when the box is removed'from contact with the wall, I provide a shutter device such as that shown in Figs. 12 and 14, which comprises a flap 109 hinged to the inside of `the box, and adapted to fall by gravity, or be held by the pressure of a spring over the opening. A lever 110 may be provided for lifting this flap, the shaft of the lever passing through a bearing box 111 in-the end of the camera box 'and having an operating handle 112.

For controlling the admission of the beam of light through the opening 106 and the slit 105 to the interior of the camera box to act upon the sensitized film 94, I provide certain mechanism which I will now describe: Upon the main frame adjacent to the camera box I secure a box 113 having an opening 114 in its front wall in line with the opening 106 in its rear wall. The opening 114 is controlled by shutter 115 mounted upon the vertically movable standard 116, to the lower end of which is secured the armature 117 of the electro-magnet 118. The armature 117 is preferably so disposed that it tends to drop away from the magnet 118 by gravity, but in order to insure operation of the shutter and increase its speed, I preferably place above it a compression spring 119. In order to raise the shutter 115 and expose the opening 114, and to bring the armature 117 into the field of magnet 118 at stated intervals, I journal in the diaphragm box 113 a shaft 360 having mounted thereon a cam ,120 adapted to engage an arm 121 projecting from the standard. This cam has a portion of increased radius 122 which acts when the cam is rotated to raise the armature and open the shutter, and has an abrupt offset at 123, so that when rotated it permits the shutter to instantly close under the action of gravity and of the spring 119, unless at the time this offset is reached the magnet.

118 is energized.

The shaft 360 is driven from the main driving shaft 73 through gearing 125 and the shaft 126, which carries bevel gear 127 engaging with a bevel gear 128 fixed to the shaft 360. The latter shaft is provided with a spur gear 361 which `engages with a spur gear 362 on a shaft 124. The gear 129 on shaft 124 engages with the gear 130 upon the shaft 131, the gear 130 also meshing with the gear 132 fixed to the shaft 133. The shafts 124, 131 and 133 carry the light controlling diaphragms which form an "1m-- portant feature of my invention.

The light controlling or aperture-forming diaphragms are shown in transverse section and plan in Figs. 14V and 15, respectively, and are shown in rear elevation on an enlarged scale in Fig. 18. They comprise a pair of eccentric, disks 134 secured to shafts 124 and 133, and a disk 135 having twice the eccentiicity of the disks 134 and mounted on shaft 131. The disks need not be complete eccentric's as but about one-half of the edge of each disk is actually used in forming the light aperture 136 and their active edges should, to be theoretically exact, be arcs of Archimedean spirals rather than circular arcs. In practice, however, I find that satisfactory results are obtained by making the disks circular and giving them a slight eccentricity. These three disks form three sides of the aperture 136, the fourth side being formed by the stationary diaphragm 137. In Fig. 18 the aperture 136 is shown at its maximum size, it being understood that when the disks are rotated so that their points of greatest radius are` adjacent, the aperture 136 will either be reduced to a very small area or closed entirely. One of the disks, preferably the disk 135, is provided with an extension 138 forming a shutter which acts immediately after the maximum size of aperture has been reached to clcse the aperture entirelyuntil it has reached its minimum;.the aperture is then uncovered again and slowly grows until the maximum '1s again reached. In order to prevent diffusion of the light through the aperture 136, I preferably mount adjacent to the same a pieceof ground glass, or similar translucent material 139, this material being preferably secured to the stationary diaphragm 137 as shown. The diaphra Ins serve to expose a larger or smaller sur ace of this illuminated screen, the image of which is photographed upon the sensitized film 94. A suitable lens 140 is provided for focusing the illuminated square upon the film, in order to give a sharp outline thereto. The disk 135 is given twice the eccentricity of the disks 134, and the fourth side of the aperture 136 is formedl by the statlonary diaphragm 137 in order to compensate for the continuous movement of the film carried on drum 93. Owing to this movement the film uncovers itself beyond the edge of the diaphragm 137 at the same rate thatthe exposed portion of the film grows laterally, the effective opening of the diaphragm 135 being decreased to a like amount. The effect is thus produced of 1an aperture opening equally in all directions, and the resultant exposed portion or dot grows from a fixed center equally on all sides.

In order to maintain a positive relation between the moving diaphragm, the shutter opening cam and the drum 93, these parts are all geared together and driven from a common driving shaft, as already described. The result is to insure themaking of the several. exposures upon the recording film -at equally spaced intervals, that is, the centers of successive exposed portions or dots are equally spaced. From the nature of half-tone plates it will .be understood that the sending half-tone shown in Fig. 1 is composed of parallel rows of dots, the dots in` adjacent rows being staggered, so that the rows do not begin at equal distances from the edge of the plate; moreover, every alternate row will have one dot less than the preceding row. In order to produce asimilar arrangement of dots on the record film, it is necessary to so proportion the gearing between the drum 93 and the diaphragm and shutter mechanism that the latter will go through a number of cycles equal to the mean number of dots per row for every revolution of the drum, that is to say: For the first revolution of the drum, supposing the number of dots in the first row of the sending half-tone to be 100, the diaphragm and shutter mechanism will go through 99% cycles. During the second revolution of the drum the shutter mechanism will again go through 99% cycles, although the number of dots 1n the second row is only 99. This result may be readily accomplished by properly proportioning the drum driving gear 90 and its driving worm 89. For eX- ample, if the number of dots in the long row of the half-tone is 100, the gear 90 should have 199 teeth, the worm 89 being given a double thread.

The movable diaphragms and their driving mechanism as above described serve to locate the exposed portions or dots upon the film, with their centers arranged in the same relation as in the sending half-tone, and also serve in combination with the drop shutter 115 to determine the size of the eX- posed portions. This size is fixed by the period after the commencement of the opening of the aperture 136, at which the drop shutter falls, as the exposed portion upon the film grows continuously owing to the enlargement of the aperture 136 until the light is cut off by the dro-p shutter. y

In order to maintain the cycles of the sending and receiving machines in such relation to each other that the exposures of the receiving film mav be madeat proper times to correspond with the impulsesy being transmitted by the sending machine so that the drop shutter will be operated at proper intervals, the sending and receiving machines may be operated in synchronism. In

this case it will be necessary to so drive the machines that a brush 19 reaches and passes over Athe center of each successive dot at the same instant that the diaphragms commence the formation of the aperture 136. To maintain the machines in synchronism, however, is a matter somewhat difficult ofaccomplishment, and I have devised means by which this may be avoided, which I regard as animportant feature of my invention. I accomplish this result by in effect sending each dot as a separate operation and recording the same before beginning the transmission of the next dot.

The mechanism by which I send and re- 80` ceive the single impulses and control the relative o eration of the two machines is as follows: eferring to the diagram of the electrical circuits at the receiving end of my apparatus, Fig. 23, it will be seen that the main circuit wire 56 connects with the relay 141, which is connected by the wire 142 to the back contact 143 of the relay 144. The armature 145 of this relay is connected by a Wire 146 to the back contact 147 of a relay 148, the armature 149 of which is connected to the main line wire 57. It will thus be seen that the main line circuit passes through the relay 141 and is closed only when the circuits of relays 144 and 148 are open. The relay 141, I call the main line relay, and when energized it acts to close what I call the primary circuit. This circuit starts from the main line relay contact 150, from which wire 151 leads to the primary magnet `100 152, Wire 153 leading from the latter to the first primary relay 154. The circuit then continues successively through wire 155, second primary relay 156, wire 157, third [primary relay 158,wire 159, fourth primary relay 160, wire 161, fifth primary'relay 162, wire 163, battery 164, wire 165, wire 166, through the shutter magnet 118 and wires 167 and 168 back to the armature 169 of the main line relay 141. It will thus be seen that whenever the main line relay 141 is energized, the primary magnet 152 will be energized, the shutter magnet 118 will be energized, holding the shutter open if its armature has been moved into proximity therewith bv the cam 120, and the several primary relays 154. 156, 158, 160 and 162 will be energized. The main line relay 141 will be closed whenever the main circuit is closed, unless the circuits of either relays 120 144 or 148 are cle-sed. The purposes of these two relays and their modes of operation will be fully described hereinafter.

The primary magnet 152 and its driving. mechanism is more fully shown in Figs. 5, 6, 8 and 9. From these figures, and particularly Fig. 8, it will be seen that` the primary magnet 152 is carried by a cross head 170, slidably mounted upon guides 171 supported on the main frame 74 of the re- 130 ceiving apparatus. The cross head 170 carrying with it the primary magnet 152 is reciprocated by means of a pitman 172 connected to a crank 173 mounted upon the end of the vertical shaft 174. This shaft carries a gear 175 which meshes with a gear 176 fixed to a shaft 177, which is driven through suitable gearing 178 from the main driving shaft 73. The shaft 174 has fixed to it a cam 179 which engages the contacts 180, holding the same closed during substantially a half revolution of the cam shaft. The cam is so placed as to be out of engagement with the contacts 180 during the movement of the primary magnet 152 in the direction indicated by t'he arrow, which I call the forward stroke of the magnet, the contacts being closed during the movement of the magnet in the opposite direction. I also provide arsecondary magnet 181, which is mounted upon a cross head 182, slidably mounted upon guides 183. A pitman 184, connected to a crank 185 fixed to the end of the shaft 186, serves to reciprocate the secondary magnet 181", the shaft 186 being driven through a gear 187 from the gear 176 above described. The shaft 186 has secured to it a ca1n188, similar to the cam 179 on the shaft 174, and engaging with a pair of contacts 189. The cam 188 closes the contacts 189 during substantially the same period that thecontacts 180 are closed, though it may be advantageously arranged to permit the contacts 189 to open slightly before the contacts 180 are open. It is to be noted that the crank 185 is twice the length of the crank 173, whereby the secondary magnet 181 has 'i twice the throw of the primary magnet 152,

and therefore moves at twice the velocity of the latter. The circuits to the magnets 152 and 181 may be made through the guides 171 and 183, respectively, as shown, or in any other suitable manner.' Slidably mounted between these two magnets in a channel 190 secured to the main frame 74, is a floating armature or movable contact member 191 adapted to be attracted by either of the magnets 152 or 181, whichever happens `to be energized at a yparticular time, and to be f moved in the direction in which the magnet by which it is at the time attracted is mov^ ing. It will be seen that whenever the armature is attracted by the magnet 152, it will `move at one-half the speed of that at which it would move if attracted at a correspond.

ing time by the magnet 181. Wire 192 makes a permanent contact with the armature 191 and at one end of the channel 190 is a contact 193fwith which the armature engages at the beginning and end of its travel. Fig. 10 shows this contact and one end of the mting armature or movable contact in detai 350 is 'a stop` for'limiting the movement of the armature, being preferably made adjustable in order to locate the end of the armature 191 properly between the contacts, and to provide for taking up wear.

Considering now the operation of the parts just described, supposing the parts to be in the position illustrated in the diagram Fig. 23, the primary magnet 152 moving in the direction indicated by the arrow, or in a forward direction, and the main circuit to be closed by the first brush 19 coming in contact with the edge of one of the conducting dots 21, the relay 141 will be energized, closing the primary circuit through the primary magnet 152, the shutter magnet 118 and primary relays 154, 156, 158, 160,162.

yIn the normal condition of affairs, the circuits through the relays 144 and 148 will be broken. The magnet 152 being now energized, will move the armature 191 in the direction of the arrow, thus breaking the contact between the same and the contact 193. as indicated. The circuit which includes the contact 193 comprises wire 194, battery 195, wire 196, relay 197, wire 198, relay 199` wire 200, relay 2,01, wire 192, and the fioating armature l91;` thus the breaking of this circuit causes the denergizing of relays 197, 199 and 201. The denergizing of relay 201 permits its armature 202 to be drawn against its back contact 203, which closes 'a circuit through wire 204 and battery 205, wire 206, wire 167, the shutter magnets 118, wire 166 and wire 207, thus energizing the shutter magnets and causing I 220, provided relay 162 is denergized and the circuit through relay 218 is closed. Relay 162, which is one .of the primary relays Yabove described, is closed only when the main line is closed, that is, when an impulse 1s comlng over the same from the sending machine; consequently the circuit last de` scribed which passes through the secondary magnet, and which I accordingly call the secondary circuit, can only be closed when no impulse is coming over the line. The circuit from relay 218 is made through wire 221 to one member of the cam operated contact 180; thence from the other member of this contact through wire 222, relay 223, n

wire 224. battery 225 and wire 226, so that relay 218 is energized only when cam 179 is acting to close the contact 180 which, as has been above described, takes place during the back stroke or half-revolution during which the primary and secondary magture circuit acts to draw its armature 227 into engagement with contact 228, which closes a circuit through wire 229, contact 230 and armature 231 of relay 232, wire 233, Contact 234 and armature 235 of primary relay 160, wire 236, relay 237, wire 238, battery 239 and wire 240, provided relays 232 and 160 ,are energized. The latter being one of the primary relays, is energized whenever an impulse is coming over the main line, while the relay 232 is contained in the circuit comprising Wire 241, contact 189, wire 242, battery 243 and wire 244. Contact 189' is closed by cam 188 from the beginning of the back stroke, that is, from the point when the primary and secondary magnetsl are farthest from the Contact 193, until they approach almost if not entirely .to the limit of their travel adjacent to contact 193. The relay 237 acts when energized to draw its armature 247 against its contact 248, thus closing a circuit through wire 249, clutch-magnets 77, wire 250 and battery 251, thus energizing the clutch magnets, drawing the clutch member 75 out of engagement with member 72 and permitting the machine to be dropped to half speed. -The conditions necessary then to dropping the machine to half speed are seen to be 1) that the primary and secondary magnets are on their back stroke, (2) that the armature 191 is in engagement with the contact 193, and (3) that there is an impulse coming over the main line.

The relay 223 acts when energized to draw its armature 252 against its contact 253, thus closing a circuit through wire 254, relay 148, wire 255, battery 256, wire 257, back contact 258, and armature 259 of relay 156,

wire 260, contact 261, carried by a bar 262 of the double switch 263 to be hereafter described, fixed contactl 264 of the double switch, and wire 265, provided relay 156 is denergized, which, as this is one of the primary relays, will be whenever there is no impulse coming over the line, and provided the double switch is in the position shown in the diagram, which is its normal condition throughout the sending of a row of dots, its condition being only changed at or near the end of a row of dots. Relay 223 being in the circuit controlled by contact 180 and cam 179, as above described, is energized only during theback stroke of the primary and secondary magnets. It will thus be seen that an impulse on the main line having terminated, thus denergizing relay 156 and permitting its armature 259 to engage its contact 258, the primary and secondary magnets being on their back stroke, the circuit through relay 148 will be closed, thus breaking the main line, so long as the primary and secondary magnets are completing the back stroke which, at the time, they are on. The breaking of the main line stops the sending machine, as has been above described, so that an impulse cannot be sent until the primary and secondary magnets start again on their forward stroke. The completion of the record of one impulse is thus insured before the coming of another.

The apparatus as thus far described comprises the means for sending and recording dots throughout each row of dots.

,f Considering the operation briefly, if now it be imagined that a small dot is to be transmitted and recorded, the impulse may reach the receiving machine at any time after the primary and secondary magnets start on their out-stroke, that is, in the direction indicated bv the arrow. It may be that the impulse will be received soon after the primary magnet starts, say for purposes of,

illustration, when the primary magnet has made one-sixth of its outward journey, and lasts until perhaps two-thirds of the outward travel of the primary magnet has occurred. In that case the primary magnet will seize the armature 191 and move it away from contact 193 for a distance equal to one-half of its full travel. Although the impulse has now ceased, the mechanism of the receiving machine continues to be driven by the motor 69 and the primary and secondary magnets continue on their outward travel, without, however, moving the armature, until they reach the end of the out-stroke. At this time the cam 120 will have raised the shutter to open position where it will be held by the magnet 1,18, the circuit through which is closed by the denergizing of relay 201, in the manner already described. At this time the movable diaphragms 134 and 135 will be in position to commence the formation of an aperture 136, and cams 179 and 188 will close contacts 180 and 189, re-

spectively. The continued operation of the diaphragms 134 and 135 will cause the aperture 136 to slowly increasein size, while at the same time the primary and secondary magnets will start on their back stroke. Relay 218 being now energized by the closing of contact 180 and the main line being broken, the secondary circuit will be closed, thus energizing the secondary magnet 181 and causing the same to seize the armature 191 and move the same toward the contact 193. This continues until the armature engages the contact, when the circuit is closed through relays 201 and 199. The ,energizing of the former breaks the circuit through the shutter magnet, permitting the shutter to close, while the energizing of the latter' Y ter open.

breaks the circuit through the secondary magnet, thus permitting it to release the armature in engagement with thelcontact 193.

The'dropping of the shutter 115 determines the exposure which has been taking place through the constantly growing aperture 136, and therefore fixes the size of the exposed portion or dot upon the recording film. The area of this dot is thus a function of thelength of impulse, being dependent upon the time taken by the armature 191- to move from the position at which it was at the beginning of the back stroke, when the aperture 136 began to grow from a zeroy riod in the operation of the receiving ma-l chine; for instance-when the primary and secondary magnets have completed a large part, say three-quarters, of their out-stroke. In that case the primary magnet will be energized, `seizing the armature 191 and moving the same for a small distance away from the contact 193. At the beginning of the return stroke the shutter will have been opened and the diaphragms will form the minimum aperture 136, as above described, thus beginning the exposure. The impulse being still on the main line, the priumary circuit will remain closed, and as it passes through the shuttermagnet 118 will maintain the same energized and the shut- The secondary magnet 181 will remain denergized at this time for the reason that the circuit through it cannot be closed While the primary circuit is closed. This is the case for the reason that the circuit through the secondary magnet includes the armature 211 of one of the primary relays 162, so that when the primary circuit is closed and the relay 162 energized, they armature 211 will be withdrawn fromits contact 212 and the circuit through the secondary magnet 181 broken at that point. The primary magnet will also remain energized and thus drag the armature 191 back toward the contact 193, the engagement with which, if the same is reached at the same instant that the impulse over the main line ceases, will permit the shutterto drop,`

making an exposure of perfect size. It will be seen that under these conditions the armature 191 will be moved out by the primary magnet during one-half of the immature from its out position into engagement with the contact 193, rwill be the same in each case, for, although in the iirst case it `must be moved twice the distance, it will be carried by the secondary magnet which moves at twice the speed of the primary magnet.

Another condition which may arise/is that the primary magnet may take the armature out a certain distance and but a part ofthe way back before the impulse ceases. In that case the primary circuit will break, deenergizing vthe primary magnet, but the shutter magnet 118 will remain energized by means of the local circuit closed through armature 202 and back contact 203 of relay 201, which is denergized. The breaking of the primary circuit denergizes relay 162 and permits its armature 211 to engage its back contact 212, thus closing the secondary circuit, the cam 179 having already closed contact 180 and consequently energized relay 218. The secondary magnet is thus energized and picks up the armature 191, carrying it the remaining distance to the contact 193 at double the speed at which it was previously moved, the exposure being terminated as before, when the armature reaches the contact. The time taken to return the armature from its out-most position to the contact 193, irst under the influence of the primary magnet, and then under the inuence of the secondaryiV magnet, will be just suiicient to produce the desired exposure. This will be seen when it is considered that the maximum length of dot on the sending plate will produce an almost continuous impulse on the main line-that is, the impulse will come at practically the beginning of the cycle of the receiving machine and continue practically to the end of it. As has been'explained, however, the diaphragms increase the size of aperture 136 from zero to maximum during the second half of the cycle only; that is, while the primary and secondary magnets are on their back. stroke. The maximum impulse is thus recordedin half the time reuired to transmit the same overthe main line, and the same ratio holds true for impulses of less length. The movement of the armature 191 from'its extreme outer position into engagement with contact 193, under the inuence of the slow movin primary magnet, will thus record a ot of maximum area.

Taking now for purposes of illustration a dot of one-half maximum area, it will be seen that the latter may be produced in any of the following ways:

First, the primary magnet may seize the armature at the beginning of its out-stroke and move the same through its entire outstroke, thus carryingthe armature to its exdtreme position. rIhe armature at the beginning of the return stroke will then be seized by the secondary magnet which will return the armature to the contact in one-half the time taken to carry itout, thus producing one-halfof the maximum exposure.

Second, the impulse may arrive after the primary magnet has made a portion of its out-stroke, for example, one-half, in which case the armature will be carried only onehalf off'its extreme distance from the contact 193. The impulse, however, has been only one-half received over the main line, so that it will continue during the -first half of the back stroke of the primary and secondary magnets. The primary, magnet will thus remain energized, the circuit to the secondary magnet being broken so that the primary magnet will move the armature back, the impulse ceasing as the primary magnet causes the armature to engage the contact. The time taken by the primary magnet to move the armature through onehalf its maximum travel is the same as the time taken by the secondary magnet to move the armature through its entire travel, so that the exposure is in both cases the same. In the third case the impulse may arrive when the primary magnet has made somewhat less than one-half of its outward travelfor exampleone-quarter, in which case the primary magnet will move the armature out three-quarters of its maximum distance. The impulse being now but threequarters expended, the primary magnet will remain energized, moving the armature back one-quarter of its maximum travel at the slow speed, which is sufiicient to give an exposure one-quarter of the maximum. The impulse now ceasing, and the armature being still away one-half of its travel from' the contact 193` the secondary magnet will become energized, and, seizing the armature, will return it to its initial position. The movement of the armature through one-half of its maximum travel, under the infiuence of the secondary magnet, occupies sufficient time C.to produce one-quarter of a maximum exposure, so that the two movements imparted to the armature,- irst, by the primary magnet, and then bythe secondary magnet, together occupy a time suiiicient to produce one-half of the vmaximum exposure, which is the result desired.

One other contingency` may arise in the operation of my device: to"w it, when an impulse arrives late, that is, when the sending machine is behind or running slower than the receiving machine..l Suppose, for instance, an impulse arrives just before the primary and secondary magnets have reached their extreme outer positions, in which case the primary magnet will-have an opportunity to move the armature 191 but a very short distance away from contact 193, the impulse continuing after the primary `and secondary magnets start on their return stroke. In that case the primary magnet continues to carry the armature and the primary circuit to energize the shutter magnet 118. The armature 191 having been carried but a very short distance away from the contact 193 is s'oon brought back into engagement therewith, but the exposure is not terminated as the primary circuit is suiicient to hold the shutter open. The exposure will accordingly last until the impulse is terminated. Considering a concrete illustration, an impulse of one-half the maximum length arrives when the primary magnet has moved through three-quarters of its outward travel. In that case the armature 191 will be moved by the primary magnet one-quarterfof its maximum distance from the contact 193, during the iirst onequarter of the impulse, when it willstart on its return travel, being moved by the primary magnet back intoengagement with the contact 193 during the second quarter of the impulse.

It will now be seen that but half of the while the diaphragms have been opened for a time suflicient to form one-quarterof a.

maximum aperture, or one-half of the desired aperture. As has been already explained, however, the diaphragms act to open an aperture of the sizexfnecessary to record anV particular impulse in a time equal to one-half the length of that impulse,

so that under the presentY condition there is still suiiicient of the impulse left to permit the diaphragms to open from zeroto the Ydesired size. As they have already opened one-half of the necessary amount, however, it will be seen that unless their rapidity of opening is checked they will have opened too far at the time the impulse\ceases, `thus producing too large an exposed area on` the record film.\ I accordinglyv provide the means already 'described for dropping the apparatus to half speed, whenjthe armature 191engages the contact 193 and the impulse is still on the main line. This operaf tion, it will be understood, occurs through the energizing of relay 197 which closes the armature 227 upon contact 228, thus closing the circuit through relay 237. As' the circuit is closed between armature 231 and contact 230, owing to the action of cam 188, and also between armature 235 and ,Contact 234. as the impulse is still on the main line and the primary circuit consequently closed,

the energizingy of relay 237, as has been above described, closes the circuit throu h clutch magnets A77` which disconnects t e full speed driving gear from the motor 69 and permits the half speed gear to come into operation. The rate of opening of the diaphragms is thus reduced one-half, and

the remaining half of the impulse is just sufficient toY permit them to complete the formation of the desired size of aperture. Just at or before the time at which ,the primary and secondary magnets reach their initial position, the cam 188 permits the contact 189 to open, thus breaking the clutch operating circuit and permitting the apparatus to resume its normal speed. The

dropping of the receiving apparatus to half speed, besides completing the record of the impulse being received, also gives the sending machine-time to catch up with the receiving machine, so that the two are ready to start off with the next impulse more' nearly in synchronism. The mode of operation above described permits my machine to record properly a solid black such as is ,caused by the running together from the` sending plate of several dots of maximum size. This occurs quite frequently unless special care is taken in making the plate to avoid it. With my apparatus the main line simply remains energized, holding the shutter 115 raised and permitting a :continuous exposure, or rather a series of maxlmum exposures, to be made.

The means above described thus serve, by

delaying the operation of the receiving machine when it is faster than Vthe sending machine, to prevent its acting out of step with the latter, so that each dot or impulse is received and recorded by the receiving machine before the latter can pass into the conditionffor receivinga'second dot or impulse. On Athe other hand, if the sending machine is operated at a higher -fspeed than the receiving machine, impulses. can be received by the latter so long as they do not `magnets start on their out-stroke.

ing the sending machine to stop in the man-4v ner already described. The circuit of relay 148 and mannerY of closing the same have also been described, this action being controlled by t e cam 179 which acts to close the contact 80 during the back stroke of the primary and secondary magnets.

My apparatus thus acts to transmit each dot or impulse as an individual operation,

the sending and receiving machines controlling each other at such intervals-at every impulse if necessary-as to maintain their relative conditions for sending and receiving dots within the required limits. It will thus be seen'that neither synchronism nora uniform speed for either my sending or receiving machine is necessary, but that each dot or impulse is automatically sent and completely and perfectly recorded in its proper relation to the other dots or impulses.

Considering now the operation upon a brush reaching the end of a row of dots on the sending plate: If the apparatus is adjusted so that the sending and receiving machines operate in synchronism, and also if the distance between the successive brushes 19 is such that the second brush 19 is in a position to make .contact with the first dot in the second row of dots immediately after the first brush leaves the last dot in the first row, the operation of the apparatus will continue without interruption as if the dots were all in a continuous long row. This condition of affairs may, however, sometimes be difficult to obtain in actual practice, and I therefore prefer to proceed intherv 'following manner when the end of the row is reached :In the first place, I enlarge the distance between the successive brushes 19 so that the first brush 19 will have passed over a space equal to one or more dots before the second brush is ready to contact with the first-dot on the second row. l'During this space, of. course, no impulses pass over the rmain line. I mount upon some moving portion of the receiving apparatus, preferably upon the`h`ub of gear 90, a knife contact 266 so disposed that a short time before the end of the row is reached, preferably about one dot before, this contact, which of course with the gear 90 and the sha-ft 91 makes one revolution for every revolution of the lfilm carrying drum, will engage with a pair of contact springs 267, thus closing the circuit through wire 268, magnet 269 and wire 270, the magnet 269 acting to throw the double switch 263, which comprises the armature 271 of the magnet 269, the armature 272 of 'Y the magnet 273 and the connecting bar 262 of insulating material, this bar carrying the three contact blocks, one, the block 261, already described, @te which wire 260 is connected and with which brush 264 makes contact, and the contact blocks 27 4 and 275.Y It will be seen that the throwing over of this double switch brings the block 275, which is permanently connected to the wire 276, -un

der the brush 277, which is connected with the wire 278. The wire 278 has branches 279 and 280 leading, respectively, to relays.

281 and 282, from the former of which a wire 283 leads to a point 284, from whichy it vbranches, one branch 285 going through :the:

armature 286 ofthe relay 281, this Varmature being adapted to be ,drawn by the relay, when energized, into contact with the `con tact 287, which is connected by wire 288 with armature 289 of relay 290, which amature is normally in contact with the back contact 291; wire 292 leads from the latter to the main line breaking relay 144 from which a wire 293 leads to battery 294, from which the wire 276, mentioned above as being connected with contact block 275, starts. From the point 284 the second branch 295 of wire 283, above-mentioned, leads to the contact 296 of the delayed circuit 'closer shown in Fig. 19. This circuit closer comprises the magnet 297 having, the armature 298 in which is a guide-groove 299. In the guidegroove slides longitudinally a bar-300 which has at its outer end the contact 301 and which carries a toothed block v302. The bar 300 is adapted to be normally telescoped with the armature by means of the contractile spring 303 .which is secured to the block.

302 and to some fixed part of the armature. The delayed circuit closer is also provided with a shaft 304 which carries a screw 305 at its outer end, the shaft 304 being continuously rotated in any suitable manner, `as by means of a gea-r 306 meshing with a pinion onshaft 126. The magnet 297 is connected by a wire 307 to the back contact 308 of relay 282, the armature 309 of which is connected by a wire 310 to the back contact 311 of relay 158; armature l312 of the latter relay from which wire 315 leads to the magnet 297. The contact 301 on the end of the telescopic bar 300 is electrically connected, preferably through the armature 298, to the'wire 316 which connects with the battery 317,

from which wire 318leads to relay 282. From the latter, wire 280 leads to the junction of wires 279 and 278, as already described.

The operation of this delayed circuit closer is as follows: Assuming iirst, for the nioment, that the end of the row has not been approached and that the double switch is in its normal position, as shown in the drawings, it will be seen that whenever the main circuit, and consequently the primary circuit, is broken, relay 158 will be denergized andthe circuit will be closed through armature 312, back contact 311, wire 310, armature 309, backcontact 308, wire 307, magnet 297, wire 315, battery 314 and wire 313. This will energize the magnet 297,

causing it to draw down its armature 298,

which will *bring the teeth on block 302 into engagement \with the thread on screw 305.

As this screwsis constantly rotating it will cause the block302, acting as a nut, to travel longitudinally thereon, thus drawing the bar 300 outwardly against the tension ofythe spring 303 until the contact 301 touches the contact 296. At that moment a circuit will is connected by a wire 313 to battery 314 be closed through 296, wire 295, wire 283, relay 281, wire 279, wire 280, relay 282, wire 318, battery l317, wire 316 andarmature 298.

"Relay 282 will' thus become "energized, drawwill never be carried far enough to engage contact 296. No harm is done, however, if it does engage contact 296, as the circuit will then be broken by relay 282, as above-described. It will thus be seen that the delayed circuit closer has, no function during the normal operation of the machine, that f is, when the double switch 263 is in its normal position, which is the position shown in the drawings. When, however, the end of the row'is approached, and the knife 266 closes the circuit between the springs 267, causing the magnet 269 to draw the double switch 263 into its second position, it will be seen that brush 277 engages block 275, as above set forth, and wires 278 and 276 are connected. A circuit now extends from contact 301 through armature 298, wire 316, battery 317, wire 318, relay 282, wire 280, wire 278, brush 277, block 275, wire 276, battery 294, wire 293,-relay 144, wire 292, back contact 291, armature 289, wire 288, contact 287, armature 286, wire 285 and wire 295 to contact 296, this circuit being, however, broken between 287 and 286, and 301 l and 296. The brush 19 continues to sweep over the few remaining dots on the line, each time making and breaking the main circuit and the primary circuit 'which passes through relay 158. This relay acts, therey again breaks the circuit through magnetl u 297. In ythe short space of time, however, during which the circuit through relay 282 is closed, a circuit is also closed through relay 281 whichcauses armature 286to be drawn over into contact with contact 28,7.

A circuit is thus established through relay .144, as above described, this circuit including relay 281, so that the latter is maintained 

